Heat dissipation structures for crankshaft dampers

ABSTRACT

A crankshaft damper for attachment to one end of a crankshaft of an engine. The crankshaft damper includes an elastomeric member attached to a hub, and an inertia ring connected to the hub through the elastomeric member. Several different structures for cooling the elastomeric member are disclosed that dissipate heat away from the elastomeric member. Air flow is induced near the elastomeric member by providing air flow openings in the inertia ring or the elastomeric member.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.15/832,146 filed Dec. 5, 2017, now U.S. Pat. No. 10,393,220 issued Aug.27, 2019, the disclosure of which is hereby incorporated in its entiretyby reference herein.

TECHNICAL FIELD

This disclosure relates to an engine crankshaft damper for enginesoperating at high temperatures.

BACKGROUND

Crankshaft dampers are used to reduce torsional deflections incrankshafts of combustion engines. Crankshaft dampers function byconverting torsional deflections into heat which reduces the crankshafttorsional deflections to increase the life of a crankshaft. Crankshaftdampers may be of the elastomeric type or of the viscous fluid type.This disclosure is directed to elastomeric type crankshaft dampers.

Crankshaft dampers are typically attached to the front end of the engineand are normally enclosed in confined spaces. Heat from the engine andother components such as turbochargers, and the like, creates highambient temperatures in the engine compartment. Heat is also conductedfrom the engine to the crankshaft damper. The high ambient temperaturesand heat conducted by the engine add to the heat created by damping thetorsional deflections of the crankshaft.

Elastomeric crankshaft dampers generally include a rigid hub that issecured to the crankshaft. An inertia ring is attached to the hub by anelastomeric member which may be shaped as a ring or a disk. Vibrationsof the crankshaft are damped by torsional shearing of the elastomericmember relative to the inertia ring. The inertia of the ring and thetorsional spring rate of the elastomeric member are selected to providea specific natural frequency, at which resonance occurs resulting inmaximum heat generation in the crankshaft damper to minimize crankshaftdeflection.

All crankshaft dampers, including both viscous and elastomericcrankshaft dampers, have operating temperature limits based on theirdesign and the temperature resistance of the damping materials. Recentlyreleased high temperature crankshaft damper elastomers have a highertemperature limit than other types of crankshaft damper elastomers andviscous fluids. However, some applications may exceed the temperaturelimit of these high temperature crankshaft damper elastomers and, as aresult, there is a need for improvements in elastomeric crankshaftdampers to obtain greater heat dissipation.

This disclosure is directed to solving the above problems and otherproblems as summarized below.

SUMMARY

According to one aspect of this disclosure, a crankshaft damper isdisclosed that is adapted to be attached to one end of a crankshaft ofan engine. The crankshaft damper includes an elastomeric member attachedto a hub, an inertia ring connected to the hub through the elastomericmember, and one or more of several different structural means forcooling the elastomeric member. The means for cooling the elastomer mayimprove heat dissipation through the damper by conduction, convection,increased surface area, and/or increased air flow.

According to another aspect of this disclosure, the inertia ring maydefine a plurality of non-cylindrical openings that are larger near theelastomeric member and smaller as the spacing from the elastomericmember increases. The non-cylindrical openings may be triangular orpolygonal shaped openings and may have rounded corners. Alternatively,the non-cylindrical openings may be arcuate openings.

The inertia ring may have a back side and a front side include vanes fordirecting air axially through the openings in the crankshaft damper. Thearcuate openings may be aligned with a recessed portion between thevanes to draw air from the arcuate openings.

The crankshaft damper may include a sleeve bonded to the elastomericmember that has higher thermal conductivity than the inertia ring. Thesleeve functions to conduct away from the elastomeric member. Theinertia ring may also define a plurality of arcuate openings that extendaxially through the inertia ring and function direct air through theopenings to cool the elastomeric member, in combination with portions ofan outer surface of the sleeve.

According to another aspect of this disclosure, crankshaft damper mayinclude an inertia ring that defines a plurality of cylindricalopenings, the openings having a central axis that is circumferentiallyoffset in an axial direction and disposed at an angle relative to arotational axis of the crankshaft damper in the axial direction. Thecentral axes of the cylindrical openings may be disposed at a selectedradial distance from the rotational axis of the crankshaft damper. Thecentral axes may be oriented to open into an area in front of thecrankshaft damper to draw air from in front of the crankshaft damperthrough the openings when the crankshaft damper is rotated.

In another variation, the crankshaft damper may include an inertia ringthat defines a plurality of openings having a central axis that iscircumferentially offset in an axial direction and disposed at an anglerelative to a rotational axis of the crankshaft damper in the axialdirection. The openings may have a tapered cross-section including anintermediate portion having a reduced cross-section compared to frontand rear portions of the openings. The intermediate portion creates aventuri effect with increased air flow velocity to increase heatdissipation from an interior portion of the elastomeric member.

The hub may include a plurality of vanes that are angled to draw airfrom an area in front of the crankshaft damper to an area in back of thecrankshaft damper and the hub may define a plurality of openings betweenthe vanes.

In another variation, the inertia ring may include a front portion and aback portion that each partially define a plurality of radiallyextending arcuate vanes that define a plurality of recesses between thearcuate vanes. The front portion and the back portion may be assembledtogether over the elastomeric member with a plurality of fasteners. Thearcuate vanes are spaced apart to define air flow passages through whichair is pumped radially outwardly to cool the elastomeric member. Thefront portion of the inertia ring may further include a firstcylindrical collar and the back portion of the inertia ring may includea second cylindrical collar. The first and second cylindrical collarsare abutted when the inertia ring is assembled over the elastomericmember.

The inertia ring is connected to the hub through the elastomeric memberand the inertia ring may define a plurality of radially extending boresthat are aligned with at least one gap defined by the elastomeric memberand a second plurality of holes defined by the hub, wherein air flow isdirected radially outwardly from the hub through gap in the elastomericmember and the bores in the inertia ring. The elastomeric member mayinclude a front ring and a rear ring that define the at least one gapbetween the front ring and the rear ring. Alternatively, at least onegap may be defined by the elastomeric member and may include a thirdplurality of holes that are aligned with the first and second pluralityof holes.

In another variation, a crankshaft damper that is adapted to be attachedto one end of a crankshaft of an engine may comprise a disk-shaped hubattached to one end of the crankshaft. An inertia ring is connected tothe hub through the elastomeric member and is received in a radiallyextending slot defined by the elastomeric member. The inertia ring isattached to one radially extending side of the elastomeric member and acup-shaped case is used to secure the elastomeric member and the inertiaring together. A plurality of radially extending bores defined by theinertia ring are aligned with a plurality of holes defined by the case,wherein air flow is facilitated radially outwardly from the hub throughthe inertia ring and the case. The elastomeric member may include afirst ring and a second ring assembled on opposite sides of the hub.

In a further embodiment, the inertia ring may be connected to adisk-shaped hub through the elastomeric member with the hub beingreceived in a radially extending slot defined by the elastomeric. Acup-shaped case secures the elastomeric member and the inertia ringtogether and a plurality of radially extending bores may be defined bythe elastomeric member in alignment with a first plurality of holesdefined by the cup-shaped case and a second plurality of holes definedby the inertia ring, wherein air flows radially outwardly from the hubthrough the elastomeric member, the inertia ring, and the case. Inaddition, a plurality of axially extending bores may be defined by theinertia ring that extend from a radially extending side of the inertiaring with each axially extending bore opening into one of the radiallyextending bores.

In another embodiment, a crankshaft damper is disclosed that comprises ahub adapted to be attached to a crankshaft and an elastomeric ringdefining a circumferential slot on an inner diameter for receiving anouter periphery of the hub. First and second radially inwardlyconverging plates are assembled to a front side and a rear side of theelastomeric ring, respectively. A inertia ring is attached to the firstand second plates radially outboard of the elastomeric ring with aplurality of rivets that are received in a first set of axiallyextending holes defined by the plates and the inertia ring. A second setof axially extending holes are provided through the plates and theinertial ring hole to facilitate air flow between a forward area infront of the damper and a rearward area behind the damper.

According to another embodiment, a crank shaft damper is disclosed thatcomprises a hub adapted to be attached to a crankshaft and anelastomeric ring that defines a circumferential slot on an innerdiameter for receiving an outer periphery of the hub. First and secondradially inwardly converging plates are assembled to a front side and arear side of the elastomeric ring, respectively. An outer diameter ofthe first and second plates include notches radially outboard of theelastomeric ring. An inertia ring is attached to the first and secondplates radially outboard of the elastomeric ring that defines axiallyextending holes aligned with the notches in the first and second platesto facilitate air flow between a forward area in front of the damper anda rearward area behind the damper.

According to other aspects of the preceding embodiment, the notches maybe formed as serrations in the outer diameter of the first and secondplates, and the serrations may be pressed into the inertia ring toattach the inertia ring to the first and second plates. The notches maybe aligned with a plurality of axially extending grooves on an outerdiameter of the elastomeric ring.

Another embodiment of a crankshaft damper is disclosed that comprises ahub adapted to be attached to a crankshaft. An elastomeric ring definesa circumferential slot on an inner diameter for receiving an outerperiphery of the hub. First and second radially inwardly convergingplates are assembled to a front side and a rear side of the elastomericring, respectively, with the first and second plates having an outerdiameter outboard of the elastomeric ring. An inertia ring is attachedto the first and second plates radially outboard of the elastomeric ringand defines recesses on a front inner diameter and a rear innerdiameter. The inertia ring defines slots extending axially through theinertia ring to facilitate air flow between a forward area in front ofthe damper and a rearward area behind the damper.

Another embodiment of a crankshaft damper is disclosed that comprises ahub adapted to be attached to a crankshaft and an elastomeric ringdefining a circumferential slot on an inner diameter for receiving anouter periphery of the hub. Front and rear cast inertia ring parts eachinclude an outer ring defining a first set of axially extending holesthat are adapted to receive fasteners for securing the front and rearcast inertia ring parts together, the outer ring defines a second set ofaxially extending holes to facilitate air flow between a forward area infront of the damper and a rearward area behind the damper, wherein thefront and rear cast inertia ring parts include a front wall and a rearwall that extend radially inwardly from the outer ring in front of andbehind the elastomeric ring, respectively.

According to other aspects of the preceding embodiment, the front walland the rear wall may converge axially in the radial inward direction.The front wall and the rear wall each may have cooling fins on anoutwardly facing surface. The second set of axially extending holes maybe elongated slots. The outer ring may define a plurality of radiallyoutwardly extending slots in fluid flow communication with the secondset of axially extending holes. The elastomeric ring may define a firstset of radially extending grooves in at least one surface facing thehub, and wherein the elastomeric ring defines a second set of grooves onat least one surface facing at least one of the front wall and the rearwall. The elastomeric ring may define a plurality of axially extendinggrooves on an outer diameter of the elastomeric ring. The plurality ofaxially extending grooves may be aligned with the first and second setof radially extending grooves. The crankshaft damper may further includea tubular ring assembled to an outer diameter of the elastomeric ring,the tubular ring that has an outer diameter wall surface disposed in theaxially extending holes.

The above aspects of this disclosure and other aspects will be describedbelow with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of an engine including a crankshaftdamper attached to the front end of a crankshaft.

FIG. 2 is a fragmentary front elevation view of a first embodiment of acrankshaft damper.

FIG. 3 is a cross-section view taken along the line 3-3 in FIG. 2.

FIG. 4 is a front perspective view of a second embodiment of acrankshaft damper.

FIG. 5 is a fragmentary front elevation view of the second embodiment ofa crankshaft damper.

FIG. 6 is a cross-section view taken along the line 6-6 in FIG. 5.

FIG. 7 is a fragmentary front perspective view partially incross-section of a third embodiment of a crankshaft damper.

FIG. 8 is a fragmentary front elevation view of the third embodiment ofa crankshaft damper.

FIG. 9 is a cross-section view taken along the line 9-9 in FIG. 8.

FIG. 10 is a is a fragmentary front elevation view of a fourthembodiment of a crankshaft damper.

FIG. 11 is a fragmentary cross-section view taken along the line 11-11in FIG. 10.

FIG. 12 is a fragmentary top plan view of the fourth embodiment of acrankshaft damper.

FIG. 13 is a fragmentary front elevation view of a fifth embodiment of acrankshaft damper.

FIG. 14 is a fragmentary cross-section view taken along the line 14-14in FIG. 13.

FIG. 15 is a fragmentary top plan view of the fifth embodiment of acrankshaft damper.

FIG. 16 is an exploded perspective view of a sixth embodiment of acrankshaft damper.

FIG. 17 is a is a front elevation view of a sixth embodiment of acrankshaft damper.

FIG. 18 is a cross-section view taken along the line 18-18 in FIG. 17.

FIG. 19 is a fragmentary front perspective view partially incross-section of a seventh embodiment of a crankshaft damper.

FIG. 20 is a fragmentary front elevation view of the seventh embodimentof a crankshaft damper.

FIG. 21 is a cross-section view taken along the line 21-21 in FIG. 20.

FIG. 22 is a top plan view of the seventh embodiment of a crankshaftdamper.

FIG. 23 is a perspective view partially in cross-section view of aversion of the seventh embodiment having and elastomeric member thatincludes a plurality of holes.

FIG. 24 is a cross-section similar to FIG. 21 of the version shown inFIG. 23.

FIG. 25 is a fragmentary front perspective view partially incross-section of an eighth embodiment of a crankshaft damper.

FIG. 26 is a fragmentary front elevation view of the eighth embodimentof a crankshaft damper.

FIG. 27 is a cross-section view taken along the line 27-27 in FIG. 26.

FIG. 28 is a top plan view of the eighth embodiment of a crankshaftdamper.

FIG. 29 is a fragmentary front perspective view partially incross-section of a ninth embodiment of a crankshaft damper.

FIG. 30 is a fragmentary front elevation view of the ninth embodiment ofa crankshaft damper.

FIG. 31 is a cross-section view taken along the line 31-31 in FIG. 30.

FIG. 32 is a top plan view of the ninth embodiment of a crankshaftdamper.

FIG. 33 is a front elevation view of a tenth embodiment of a constantstress double shear disk crankshaft damper.

FIG. 34 is a fragmentary cross-section view taken along the line 34-34in FIG. 33.

FIG. 35 is a fragmentary front elevation view of an eleventh embodimentof a crankshaft damper having serrated teeth on an outer diameter ofsteel plates for securing the plates to the cast iron ring with axialholes formed in the cast iron ring to provide air channels for coolingthe elastomeric ring.

FIG. 36 is a cross-section view taken along the line 36-36 in FIG. 35.

FIG. 37 is a fragmentary front elevation view of a twelfth embodiment ofa crankshaft damper having cast oblong slots through the cast iron ring.

FIG. 38 is a cross-section view taken along the line 38-38 in FIG. 37.

FIG. 39 is a front elevation view of a thirteenth embodiment of acrankshaft damper having cooling fins on the steel plate faces.

FIG. 40 is a cross-section view taken along the line 40-40 in FIG. 39.

FIG. 41 is a front elevation view of a fourteenth embodiment of acrankshaft damper having arcuate slots in the cast iron ring.

FIG. 42 is a cross-section view taken along the line 42-42 in FIG. 41.

FIG. 43 is a cross-section view similar to FIG. 42 further including aradial slot in the cast iron ring in fluid communication with thearcuate slots.

FIG. 44 is a cross-section view taken along the line 42-44 in FIG. 43.

FIG. 45 is a cross-section view similar to FIG. 44 further includingradial grooves.

FIG. 46 is a cross-section view similar to FIG. 44 further includingaxial grooves on the elastomeric ring in addition to the radial grooves.

FIG. 47 is a front elevation view further including serrations on theouter diameter of the washers aligned with grooves in the outer diameterof the elastomeric ring.

FIG. 48 is a fragmentary cross-section view taken along the line 48-48in FIG. 47.

FIG. 49 is a front elevation view of another embodiment of a crankshaftdamper further including radial ribs formed on the steel plates.

FIG. 50 is a cross-section view taken along the line 50-50 in FIG. 49.

FIG. 51 is a cross-section view taken along the line 51-51 in FIG. 49.

FIG. 52 is a front elevation view of another embodiment of a crankshaftdamper further including a tubular ring assembled to the outer diameterof the elastomeric ring radially inboard of the axial holes formed inthe cast iron ring and with cooling fins provided on the sides of thering.

FIG. 53 is a cross-section view taken along the line 53-53 in FIG. 52.

DETAILED DESCRIPTION

The illustrated embodiments are disclosed with reference to thedrawings. However, it is to be understood that the disclosed embodimentsare intended to be merely examples that may be embodied in various andalternative forms. Features of different embodiments may be combinedwith other embodiments. The figures are not necessarily to scale andsome features may be exaggerated or minimized to show details ofparticular components. The specific structural and functional detailsdisclosed are not to be interpreted as limiting, but as a representativebasis for teaching one skilled in the art how to practice the disclosedconcepts.

Referring to FIG. 1, an engine 10 is shown that is equipped with acrankshaft damper 12. The crankshaft damper 12 has a front side 14 and aback side 16. The crankshaft damper 12 is attached to a crankshaft 18(the location of which is indicated by reference numeral 18 in FIG. 1)that extends through the lower portion of the engine 10, as is wellknown in the art.

Referring to FIGS. 2 and 3, a first crankshaft damper is generallyindicated by reference numeral 20. The crankshaft damper 20 includes ahub 24 that is enclosed within an elastomeric member 26. An inertia ring28 is assembled over the elastomeric member 26. The inertia ring 28defines a plurality of triangular openings 30 that have rounded corners32. The triangular openings 30 have a larger portion 36 and a smallerportion 38. The larger portion 36 is located near the elastomeric member26 and the smaller portion 38 is located radially outward relative tothe larger portion 36. The larger portion 36 provides a larger surfacearea for improving heat dissipation away from the crankshaft damperthrough conduction, convection, and increased air flow across thesurface. The smaller portion 38 limits the reduction of inertia causedby including the triangular openings 30. The triangular openings 30increase air flow and increase surface area. The triangular openings 30may also be referred to as a non-cylindrical opening or a polygonalopening.

Referring to FIGS. 4-9, a second crankshaft damper is generallyindicated by reference numeral 40. The second crankshaft damper 40 isshown in FIGS. 4-6. References to similar parts of the second crankshaftdamper 40 are also used with reference to FIGS. 7-9. The secondcrankshaft damper 40 includes a sleeve 42 that is preferably made of amaterial having a higher coefficient of thermal conductivity than theinertia ring 44. The sleeve 42 may be made of aluminum, steel, stainlesssteel, or another type of material having a higher coefficient ofthermal conductivity than the inertia ring 44. The inertia ring 44 maybe made of steel or cast iron or other high mass material to maximizethe inertial force applied to the elastomeric member 26.

A plurality of arcuate openings 46 are defined on the inner diameter ofthe inertia ring 44. The arcuate openings 46 are generallysemi-cylindrical in shape but may be formed in other shapes with theopenings 46 having a larger cross-sectional area near the sleeve 42 anda reduced cross-sectional area nearer to the inertia ring 44. Thearcuate openings 46 are formed in the inertia ring 44 and are alsopartially defined by the outer surface 48 of the sleeve 42.

The arcuate openings 46 may be located with respect to a plurality ofvanes 50 and recesses 52 that are formed on one or both of the frontside 14 and back side 16 of the crankshaft damper 40. The arcuateopenings 46 are aligned with the recesses 52 formed between adjacentvanes 50. The vanes 50 cooperate with the arcuate openings 46 to createan air pump that increases airflow through arcuate openings 46. Thevanes increase airflow through the arcuate openings 46. The higherthermal conductivity of the outer surface 48 of the sleeve 42 increasesheat dissipation away from the elastomeric member 26.

Referring to FIGS. 7-9, a third crankshaft damper 54 is illustrated thatis similar to the second crankshaft damper 40. Similar elements arereferred to by the same reference numerals that were used in thedescription of FIGS. 4-6 above. A third crankshaft damper 54 differsfrom the second crankshaft damper 40 because it includes a plurality ofspokes 56 that create airflow through the hub 24. The spokes 56 functionis a fan or impeller blade to draw cool air from the front side 14 ofthe crankshaft damper 54. The sleeve 42 and inertia ring 44 defines thearcuate openings 46 and function in the same manner in the thirdcrankshaft damper embodiment 54 as in the second crankshaft damper 40.

Referring to FIGS. 10-12, a fourth crankshaft damper 60 is illustratedthat includes a cylindrical opening 62. The cylindrical opening 62 isdefined by the inertia ring 66 and extends in a circumferentially offsetaxial direction as best shown in FIG. 12. The offset of the cylindricalopening 62 is oriented to increase airflow through the opening 62. Thecylindrical opening 62 has a cylindrical axis X that iscircumferentially offset and extends in the axial direction through theinertia ring 66. The cylindrical opening 62 is located proximate theelastomeric member 26 on the opposite side from the hub 24. As thecrankshaft damper 62 rotates, air is drawn in through the leading edgeon the front side 14 and flows through the cylindrical opening 62 tocool the elastomeric member 26.

Referring to FIGS. 13-15, a fifth crankshaft damper 68 is shown that issimilar in many respects to the embodiment of the fourth crankshaftdamper 60 but includes a venturi opening 70 that is defined in theinertia ring 72. A constriction 74 is formed in the inertia ring 72between a mouth 76 formed on the front side 14 and an outlet 78 formedon the back side 16. The constriction 74 functions as a venturi causingthe air velocity to be greatest at the narrow cross-section in themiddle of the inertia ring 72. The increased air velocity leads tohigher heat dissipation in the middle of the elastomeric member 26 whereheat generation caused by torsional shearing of the elastomeric memberrelative to the inertia ring.

Referring to FIGS. 16-18, a sixth crankshaft damper 80 is illustratedthat includes a front part 82 and a rear part 84 that are joinedtogether by bolts 86 or other fasteners to form an inertia ring. Acollar 88 is formed by the joining of the front and rear parts 82 and84. Collar 88 is a thin metallic collar that is assembled over theelastomeric ring 26 that is in turn assembled over the hub 24. When thefront and rear parts 82 and 84 are assembled, a plurality of internalvanes 90 are formed that are used to create airflow over the collar 88.The collar 88 is heated by the elastomeric member 26 and dissipates heatthrough the collar 88 as air flows across arcuate surfaces 92 of thevanes 90. A plurality of radial air flow passages 94 are formed betweenthe internal vanes. A plurality of air inlet holes 96 are located oneach face of the inertia ring that allow air flow into the radial airflow passages 94. Air is drawn away from the collar 88 through theradial air flow passages 94 to dissipate heat from the elastomericmember 26.

Referring to FIGS. 19-22, a seventh crankshaft damper 100 is disclosedthat includes a hub 102 that defines a plurality of holes 104 in anaxially extending flange portion of the hub 102. An inner elastomericmember 106 and an outer elastomeric member 108 are secured to the hub102 on axially opposite sides of the holes 104. A gap 110 is definedbetween the inner elastomeric member 106 and the outer elastomericmember 108. An inertia ring 112 includes a plurality of radial bores114. The radial bores 114 are aligned with the gap 110 and the hole 104to provide a radially extending hole through the hub 102 between theelastomeric members 106 and 108 and through the radial bores 114. In theseventh crankshaft damper 100, airflow through the holes 104, gap 110and radial bore 114 is used to cool the inner and outer elastomericmembers 106 and 108.

Referring to FIGS. 23-24, a version of the seventh embodiment 100A isshown that includes a plurality of holes 116 are defined by anelastomeric member 118. This version does not include the gap 110 isdefined between the inner elastomeric member 106 and the outerelastomeric member 108 because the holes 116 allow airflow through theelastomeric member 118. In all other material respects this version islike that disclosed with reference to FIGS. 19-22.

Referring to FIGS. 25-32, a different style of crankshaft damper isdisclosed. Due to the similarities in the two embodiments, the samereference numerals will be used to refer to similar parts in the twodifferent embodiments.

The eighth crankshaft damper 120 includes a hub disk 122 that receivesan inertia ring 124. The inertia ring 124 includes a first part 126 anda second part 128. The first and second parts 126 and 128 of the inertiaring 124 are axially assembled together on one axial side of the hubdisk 122. The first and second parts 126 and 128 define a plurality ofradial bores 130 that extend radially through the inertia ring 124. Anelastomeric member 132 is formed by a first ring 134 and a second ring136. The hub disk 122 is a flat disk shape and is received in a slot 138defined by the first and second rings 134 and 136. A case 140 receivesthe inertia ring 124 and elastomeric member 132 and hub disk 122. Thecase 140 is crimped over the outside of the first part 126 of theinertia ring 124. A plurality of holes 142 are defined by the case 140and are aligned with the radial bores 130 and the inertia ring 124 whenthe crankshaft damper 120 is assembled. Air flow is directed from thehub disk 122 from the inner diameter of the inertia ring 124 through theinertia ring 124 through the radial bores 130 and inertia ring 124 andthrough the holes 142 formed in the case 140. Air flows from the innerdiameter of the inertia ring 124 to dissipate heat from the elastomericmember 132 as the air flows through the holes 142.

Referring to FIGS. 29-32, a ninth crankshaft damper 148 is illustratedthat is similar in many respects to the embodiment shown in FIGS. 25-28.The ninth crankshaft damper 148 includes a radial bore 150 that isdefined by the inertia ring 124. An axial bore 152 extends from aradially extending side of the inertia ring 124 to the radial bore 150.A first elastomeric member 154 and a second elastomeric member 156receive the hub disk 122 and are sandwiched by the first and secondelastomeric members 154 and 156. A gap 158 is defined between the firstand second elastomeric members 154 and 156 that opens into the radialbore 150. The gap 158 extends from the hub disk 122 to the radial bore150. Heat is dissipated through the radial hub disk 122 from the firstand second elastomeric members 154 and 156. Heat is then dissipatedthrough the hub disk 122 and through the gap 158 to the radial bore 150.Heated air then flows through the holes 142 in the case 140.

Referring to FIGS. 33 and 34, a crankshaft damper 200 is illustratedthat includes a hub 202 adapted to be attached to a crankshaft 18 and anelastomeric ring 204 that defines a circumferential slot 206 in an innerdiameter 208 for receiving an outer periphery 210 of the hub 202. Firstand second radially inwardly converging plates 212, 214 are assembled toa front side 216 and a rear side 218 of the elastomeric ring 204,respectively. An inertia ring 222 is attached to the first and secondplates 212, 214 radially outboard of the elastomeric ring 204 with aplurality of rivets 224 that are received in a first set of axiallyextending holes 226 defined by the plates 212, 214 and the inertia ring222. A second set of axially extending holes 228 are provided throughthe plates and the inertia ring 222 to facilitate air flow between aforward area 230 in front of the damper and a rearward area 232 behindthe damper. Similar elements in the embodiment of FIGS. 33 and 34 areidentified in FIGS. 35-53 are referred to using the same referencenumerals.

Referring to FIGS. 35 and 36, a crankshaft damper 200 is illustratedthat comprises a hub 202 adapted to be attached to a crankshaft 18(shown in FIG. 1). An elastomeric ring 204 defines a circumferentialslot 206 on an inner diameter 208 for receiving an outer periphery 210of the hub 202. First and second radially inwardly converging plates212, 214 are assembled to a front side 216 and a rear side 218 of theelastomeric ring 204, respectively. An outer diameter 220 of the firstand second plates 214, 216 includes notches 234 radially outboard of theelastomeric ring 204. An inertia ring 222 is attached to the first andsecond plates 212, 214 radially outboard of the elastomeric ring 204.The inertia ring 222 defines axially extending arcuate holes 236. Theelastomeric ring 204 defines openings 235 that are aligned with thenotches 234 in the first and second plates 212, 214 to facilitate airflow between a forward area 230 in front of the damper and a rearwardarea 232 behind the damper 200.

With continued reference to FIGS. 35 and 36, the notches 234 may beformed between the serrations 237 in the outer diameter 220 of the firstand second plates 212, 214. The serrations 237 may be pressed into theinertia ring 222 to attach the first and second plates 212, 214 to theinertia ring 222. The notches 234 in the plates 214, 216 may be alignedwith a plurality of axially extending openings 235, on an outer diameter240 of the elastomeric ring 204.

Referring to FIGS. 37 and 38, a crankshaft damper 200 is illustratedthat comprises a hub 202 adapted to be attached to a crankshaft 18 andan elastomeric ring 204 defining a circumferential slot 206 on an innerdiameter 208 for receiving a outer periphery 210 of the hub 202. Firstand second radially inwardly converging plates 212, 214 are assembled toa front side 216 and a rear side 218 of the elastomeric ring 204,respectively. The first and second plates 212, 214 have an outerdiameter 220 radially outboard of the elastomeric ring 204. An inertiaring 222 is attached to the first and second plates 212, 214 radiallyoutboard of the elastomeric ring 204. The inertia ring 222 definesrecesses 242 on a front inner diameter and a rear inner diameter. Inaddition, the inertia ring 222 defines arcuate slots, or holes 236,extending axially through the inertia ring 222 to facilitate air flowbetween a forward area 230 in front of the damper and a rearward area232 behind the damper.

Referring to FIGS. 39 and 40, a crankshaft damper 250 is illustratedthat includes a hub 252 adapted to be attached to a crankshaft 18 (shownin FIG. 1). An elastomeric ring 254 defines a circumferential slot 256on an inner diameter 258 for receiving a outer periphery 260 of the hub252. Front and rear cast inertia ring parts 262, 264 each include anouter ring 266 defining a first set of axially extending holes 268 thatare adapted to receive fasteners 270 for securing the front and rearcast inertia ring parts 262, 264 together. The outer ring 266 defines asecond set of axially extending holes 272 to facilitate air flow betweena forward area 274 in front of the damper 250 and a rearward area 276behind the damper. The front and rear cast inertia ring parts 262, 264include a front wall 278 and a rear wall 280 that extend radiallyinwardly from the outer ring 266 in front of and behind the elastomericring 254, respectively. The front wall 278 and the rear wall 280converge axially in the radial inward direction. The front wall 278 andthe rear wall 280 each have cooling fins 282 on an outwardly facingsurface.

Referring to the embodiment of FIGS. 41 and 42, the second set ofaxially extending arcuate holes 272 are shown as elongated slots formedin the front casting part 262 and the rear casting part 264.

Referring to FIGS. 43 and 44, the outer ring 266 is shown to define aplurality of radially outwardly extending slots 284 in fluid flowcommunication with the second set of axially extending holes 272.

Referring to FIG. 45, the elastomeric ring 286 is shown to include afirst set of radially extending grooves 288 in at least one surface ofthe ring 286 facing the hub 252, and a second set of grooves 290 on atleast one surface of the ring 286 facing the front wall 278 and the rearwall 280.

Referring to FIG. 46, the elastomeric ring 286 may also define aplurality of axially extending grooves 292 on an outer diameter of theelastomeric ring 286. The plurality of axially extending grooves 292 areshown to be non-parallel with the radially extending grooves 288, 290.

Referring to FIGS. 47 and 48, a crankshaft damper similar to theembodiment shown in FIGS. 35 and 36 is illustrated wherein serratedwashers 298 are press-fit into recesses 242 formed in the inertia ring222. Radial grooves 294 and axial grooves 292 are provided in theelastomeric ring 286 that are aligned with notches 234 of the serratedwashers 298.

Referring to FIGS. 49-51, the illustrated damper 250 includes the firstand second inwardly converging plates 212, 214 that define a first setof radially extending grooves 294. The elastomeric ring 204 defines asecond set of radially extending grooves 296 that are aligned with thegrooves 294 when the plates are assembled to the elastomeric ring 204.An inner groove 297 may be defined by the elastomeric member 204 on aside facing the hub 202. Axially extending cross holes 269 are providedthrough the plates 212, 214 and the inertia ring 222.

Referring to FIGS. 52 and 53, the crankshaft damper of FIGS. 4 and 5 isshown to include a tubular ring 300 assembled to an outer diameter ofthe elastomeric ring 254, the tubular ring 300 has an outer diameterwall surface 302 disposed in the axially extending holes 272. Coolingfins 282 are provided on the front wall 278 and rear wall 280.

The embodiments described above are specific examples that do notdescribe all possible forms of the disclosure. The features of theillustrated embodiments may be combined to form further embodiments ofthe disclosed concepts. The words used in the specification are words ofdescription rather than limitation. The scope of the following claims isbroader than the specifically disclosed embodiments and also includesmodifications of the illustrated embodiments.

What is claimed is:
 1. A crankshaft damper comprising: a hub adapted tobe attached to a crankshaft; an elastomeric ring defining acircumferential slot on an inner diameter for receiving an outerperiphery of the hub; first and second radially inwardly convergingplates assembled to a front side and a rear side of the elastomericring, respectively; and an inertia ring attached to the first and secondplates radially outboard of the elastomeric ring with a plurality ofrivets that are received in a first set of axially extending holesdefined by the plates and the inertia ring, wherein a second set ofaxially extending holes are provided through the plates and the inertiaring to facilitate air flow between a forward area in front of thedamper and a rearward area behind the damper, wherein the first andsecond inwardly converging plates define a first set of radiallyextending grooves, and the elastomeric ring defines a second set ofradially extending grooves that are aligned when the plates areassembled to the elastomeric ring.
 2. A crankshaft damper comprising: ahub adapted to be attached to a crankshaft; an elastomeric ring defininga circumferential slot on an inner diameter for receiving an outerperiphery of the hub; first and second radially inwardly convergingplates assembled to a front side and a rear side of the elastomericring, respectively, wherein an outer diameter of the first and secondplates include notches axially outboard of the elastomeric ring; and aninertia ring attached to the first and second plates radially outboardof the elastomeric ring, the inertia ring defining axially extendingholes aligned with the notches in the first and second plates tofacilitate air flow between a forward area in front of the damper and arearward area behind the damper.
 3. The damper of claim 2 wherein thenotches are formed as serrations in the outer diameter of the first andsecond plates, and wherein the serrations are pressed into the inertiaring to attach the inertia ring to the first and second plates.
 4. Thedamper of claim 2 wherein the notches are aligned with a plurality ofaxially extending grooves on an outer diameter of the elastomeric ring.5. A crankshaft damper comprising: a hub adapted to be attached to acrankshaft; an elastomeric ring defining a circumferential slot on aninner diameter for receiving an outer periphery of the hub; first andsecond radially inwardly converging plates assembled to a front side anda rear side of the elastomeric ring, respectively, the first and secondplates having an outer diameter outboard of the elastomeric ring; and aninertia ring attached to the first and second plates radially outboardof the elastomeric ring, the inertia ring defining recesses on a frontinner diameter and a rear inner diameter, the inertia ring definingslots extending axially through the inertia ring to facilitate air flowbetween a forward area in front of the damper and a rearward area behindthe damper.
 6. A crankshaft damper comprising: a hub adapted to beattached to a crankshaft; an elastomeric ring defining a circumferentialslot on an inner diameter for receiving an outer periphery of the hub;and front and rear inertia ring parts each including an outer ringdefining a first set of axially extending holes that are adapted toreceive fasteners for securing the front and rear inertia ring partstogether, the outer ring defining a second set of axially extendingholes to facilitate air flow between a forward area in front of thedamper and a rearward area behind the damper, wherein the front and rearinertia ring parts include a front wall and a rear wall that extendradially inwardly from the outer ring in front of and behind theelastomeric ring, respectively, wherein the elastomeric ring defines afirst set of radially extending grooves in at least one surface facingthe hub, and wherein the elastomeric ring defines a second set ofgrooves on at least one surface facing at least one of the front walland the rear wall.
 7. A crankshaft damper comprising: a hub adapted tobe attached to a crankshaft; an elastomeric ring defining acircumferential slot on an inner diameter for receiving an outerperiphery of the hub; and front and rear inertia ring parts eachincluding an outer ring defining a first set of axially extending holesthat are adapted to receive fasteners for securing the front and rearinertia ring parts together, the outer ring defining a second set ofaxially extending holes to facilitate air flow between a forward area infront of the damper and a rearward area behind the damper, wherein thefront and rear inertia ring parts include a front wall and a rear wallthat extend radially inwardly from the outer ring in front of and behindthe elastomeric ring, respectively, wherein the elastomeric ring definesa plurality of axially extending grooves on an outer diameter of theelastomeric ring.
 8. The crankshaft damper of claim 7 wherein theplurality of axially extending grooves are non-parallel with a first setof radially extending grooves formed on at least one surface of theelastomeric ring facing the hub and a second set of radially extendinggrooves formed on at least one surface of the elastomeric ring facingone of the inertia ring parts.
 9. A crankshaft damper comprising: a hubadapted to be attached to a crankshaft; an elastomeric ring defining acircumferential slot on an inner diameter for receiving an outerperiphery of the hub; and front and rear inertia ring parts eachincluding an outer ring defining a first set of axially extending holesthat are adapted to receive fasteners for securing the front and rearinertia ring parts together, the outer ring defining a second set ofaxially extending holes to facilitate air flow between a forward area infront of the damper and a rearward area behind the damper, wherein thefront and rear inertia ring parts include a front wall and a rear wallthat extend radially inwardly from the outer ring in front of and behindthe elastomeric ring, respectively, further comprising: a tubular ringassembled to an outer diameter of the elastomeric ring, the tubular ringhaving an outer diameter wall surface disposed in the second axiallyextending holes.